Diffusing tip for dry chemical fire extinguisher



Feb. 5, 1957 w. HARRIS 2,780,295

DIFFUSING TIP FOR DRY CHEMICAL FIRE EXTINGUISHER Filed March 10, 1955 FIG-1 15 l as \36 a?" f 3 34 ,1 3; V 35, 1 18 23 W i z? WII/I1 INVEN TOR. WILBERT L. HARRIS ATTORNEYS United States Patent DIFFUSING TIP FOR DRY CHEMICAL FIRE EXTINGUISHER Wilbert L. Harris, Dayton, Ohio, assignor to The Fyr- 7 Claims. (Cl. 169-1) This invention relates to diffusing nozzles, particularly for use on dry chemical fire extinguishers.

The present invention is directed to obtaining effective distribution of dry chemical material sprayed from a fire extinguisher, and .to obtaining thorough diffusion of such chemical material in conjunction with distribution. In accordance with the invention it has been discovered that such extinguishers are most effective when they can supply a blanket of chemical material approximately eleven to twelve feet across the base of the flames at a ten foot range. This requires a diffusion angle of approximately fifty to sixty degrees in a horizontal plane of the material issuing from the nozzle, and it is also necessary that this blanket of chemical material be of substantially uniform consistency throughout the above mentioned eleven to twelve foot width for maximum effectiveness.

To obtain the diffusion angle of fifty to sixty degrees it was found necessary to provide a difiusion slot in the nozzle tip approximately twenty degrees greater than the actual included angle through which the chemical material is sprayed from the nozzle, to compensate for lateral constriction of the stream of material as it issues at relatively high velocity from the nozzle. In addition, it was found necessary to create turbulence in the stream of gasentrained chemical material as sprayed from the nozzle in order to obtain the required thorough diffusion of the chemical material in the spray.

It is therefore a primary object of this invention to provide a diffusing nozzle for a dry chemical type fire extinguisher capable of spraying a relatively wide blanket of chemical material which is of substantially uniform consistency throughout its width.

Another object of the present invention is to provide such a nozzle which is economical and simple to manufacture, and yet which creates the necessary turbulence in the stream of gas-entrained chemical material issuing therefrom.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

In the drawing Fig. 1 shows a nozzle of a dry chemical type fire extinguisher incorporating the diffusing tip of the present invention;

Fig. 2 is an end view of the tip incorporated in the nozzle of Fig. 1;

Fig. 3 is a section taken along line 33 of Fig. 2;

Fig. 4 is a section taken along line 44 of Fig. 2;

Fig. 5 shows a slightly modified type of arrangement wherein the tip and nozzle are mounted directly upon the extinguisher tank;

Fig. 6 is an end view of the modified nozzle used in the extinguisher shown in Fig. 5; and

Fig. 7 is a section taken along line 7-7 of Fig. 6.

Referring to the drawing, which illustrates preferred embodiments of the present invention, and particularly to Fig. 1, there is seen a nozzle of a dry chemical fire ex- 2,780,295 Patented Feb. 5,1957

tinguisher including a body 10 provided with passageways 12 and 13 joined by an oblique passageway 14 which opens outwardly of the nozzle body, such opening being closed by a suitable plug 50. Passage 12 is connected at one end 16 with a suitable coupling 17 having a central passage 18 in alignment with passage 12, this coupling serving t connect the nozzle with a hose 20 which in turn is connected to the tank of the extinguisher (not shown). An extinguisher of this type is disclosed in United States Patent No. 2,620,038 .to Charles H. Somers et al., issued December 2, 1952. A typical chemical material is a powder composed primarily of sodium bicarbonate, and this material is entrained in a gaseous stream (for example CO2) which is fed to the hose 20.

An outlet control valve is arranged to govern the flow of material through the nozzle and includes a generally cylindrical valve body 22 having a beveled end 23 and mounted for reciprocation within passageway 13 by a bushing 24. A suitable sealing ring 25 provides a gastight seal between valve body 22 and bushing 24. The beveled end 23 of the valve body seats against a washer 26 in the closed position of the valve, this washer being held in position within passageway 13 by a ring member 27 which is counterbored at its inner end to receive a suitable packing member 28 in abutment with the edge of washer 26 opposite from valve body 22.

Valve 22 is reciprocated within passageway 13 by a control handle 30 pivoted to nozzle 10 by a pin 31. Handle 30 is bifurcated between the point 32 and pivot pin 31, and a neck portion 33 of valve body 22, carrying an enlarged end 34, extends through the bifurcated portion of the handle and is arranged to be reciprocated by movement of the handle about its pivot. A suitable bumper ring 35 is placed between the end portion 34 and handle 30.

In the position shown in Fig. I, handle 30 is urged in a counterclockwise direction by a spring 36, and the bifurcated portion 32 abuts valve body 22 and urges it toward its closed position. Pressing handle 30 down against the spring will draw valve 22 away from washer 26, thereby permitting passage of the extinguishing material through the nozzle.

At the outer end of passageway 13 there is a counterbored portion 38 within which the diffusing tip, indicated generally at 40, is held by a suitable set screw 41. Referring to Figs. 24, this tip includes a generally cylindrical body 42 having a radially extending flange 43 at one end thereof, and a circular bore 44 extending substantially through said body 42 coaxially thereof. The face 45 of the tip is substantially flat, and is provided with a central horizontal slot 46, the upper and lower walls of which are shown at 47 to be substantially parallel to the axis of bore 44. The width of slot 46 is substantially less than the diameter of bore 44 so that the walls 47 form sector shaped shoulders 50 at the top and bottom of the bore 44. The ends 51 of slot 46 are generally rounded and tapered outwardly from bore 44 toward the periphery of face 45, as best seen in Fig. 4.

With the tip so constructed the difiusion angle of the stream of gas-entrained material issuing from the nozzle is quite turbulent, due to the abrupt constriction provided by shoulders 50, thereby promoting the thorough diffusion and substantially uniform dispersion of the chemical material throughout the spray as it issues from the nozzle. Satisfactory results have been obtained with a tip constructed to provide a total included angle between sides 51 of the slot of about and a combined crosssectional area of the two shoulders 50 constructed to displace about one-third the total cross-sectional area of bore 44. With such a tip, and utilizing a gas pressure of about p. s. i. the laterally widening spray pattern has an included angle of approximately. 60, providing a blanket of mate- 3 erial about 11 to 12 feet in width at a range of feet from the nozzle.

The modification shown in'Figs. 5 and 7 is designed for smaller capacity extinguishers of the dry chemical type wherein the valve and nozzle are mounted directly upon'the tank 61. An extinguisher of this type is disclosed in application Serial No. 315,112, filed October 16, 1952, in the name of Charles H. Somers and Frederick L. Beebee, and assigned to the same assignee as the present application. In accordance with the present invention a spray tip is attached to the outlet of nozzle 60, preferably by means of internal threads 66 (Fig. 7) which are received upon mating external threads of spray head 60. Nozzle 65 has a hexagonal outer surface over the greater portion of its length to facilitate tightening it on the nozzle by means of a wrench or the like. A central bore 67 extends from the internally threaded portion 66 forwardly to adjacent the flat face 63 of the tip, which has a circular periphery 69 and which is provided with a slot 70 having fiat upper and lower walls 71 and outwardly diverging end walls 72, thereby providing sector shaped shoulders 73 at the end of bore 67 in the same manner as described above in connection with Figs. 2-4. The extinguisher and nozzle of Figs. 5-7 are substantially identical in operation to the operation above described.

While the forms of apparatus herein described constitute preferred embodiments of the present invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

l. A ditfuser tip for use in a dry chemical fire extinguisher comprising a body having a face at one end thereof and a bore extending from the other end to adjacent said face, said face having a dilfusing slot therein communicating with said bore, the upper and lower walls of said slot being substantially parallel to each other and terminating along parallel lines spaced across the end of said bore by a distance less than the diameter of said bore to provide shoulders at the adjacent end of said bore on either side of said end of said slot and extending substantially transversely of said bore for creating turbulence in the gas-entrained stream of comminuted chemical material issuing from said tip, and the lateral walls of said slot divering from said end of said bore to said face relative to each other for dispersing said material in a continually laterally widening spray pattern.

2. A diffuser tip for use in a dry chemical fire extinguisher comprising a body having a face at one end thereof and a bore extending from the other end to adjacent said face, said face having a diifusnig slot therein communicating with said bore, the upper and lower walls of said slot being substantially parallel to each other and terminating along parallel lines spaced across the end of said bore by a distance less than the corresponding width of said bore to provide shoulders at the adjacent end of said bore on either side of the inner end of said slot and extending substantially transversely of said bore for creating turbulence in the gas-entrained stream of comminuted chemical material issuing from said tip, and the lateral walls of said slot diverging from said end of said bore to said face and at an obtuse angle relative to each other for dispersing said material in a continually laterally widening spray pattern.

3. A diffuser tip for use in a dry chemical fire extinguisher comprising a body having a flat face at one end thereof and a longitudinal bore therein extending from the other end to adjacent said face, said bore being substantially circular in cross-section, said face being provided with a diffusing slot opening into said bore at the termination thereof Within said body, the opening between said bore and said slot being defined by parallel chord lines extending across the circular cross-section of said bore in cooperation with the periphery of said bore joining said chord lines and providing opposed shoulders at the end of said bore for creating turbulence in the gas-entrained stream of comminuted chemical material issuing from the tip, the opposite walls of said slot terminating in said chord lines extending parallel to each other and perpendicular to said face, and the other opposite walls of said slot flaring outwardly toward the periphery of said face from each other and from said opening to provide for dispersing said material in a continually laterally widening spray pattern.

4. A diffuser tip for use in a dry chemical fire extinguisher nozzie wherein comminuted chemical material is entrained in a gaseous stream for spraying over a burning substance, comprising a cylindrical tip body adapted for attachment at one of its ends to the outlet of said extinguisher nozzle, said body terminating in a flat face at its other end, said body having a circular bore extending coaxially therein from said one end through a major portion thereof to receive the gas-entrained material from the extinguisher, oppositely disposed shoulders located at the end of said bore within said body and projecting at right angles to the walls of said bore, said shoulders terminating at their inner ends in walls parallel to the longitudinal axis of said bore and parallel to each other, the combined cross-sectional areas of said shoulders extending across said bore being less than one half the total cross-sectional area of said bore, and said face having a diffusing slot therein defined by said parallel walls and by end walls extending from the inner end of said bore outwardly to said face, said end walls flaring outwardly from each other toward said face to provide for dispersion of said material in a continually laterally widening spray pattern.

5. A diffuser tip for use in a dry chemical fire extinguisher nozzle wherein comminuted chemical material is entrained in a gaseous stream for spraying over a burning substance, the combination of a cylindrical tip body adapted for attachment at one of its ends to the outlet of said extinguisher nozzle, said body terminating in a flat face at its other end, said body having a circular bore extending coaxially therein from said one end through a major portion thereof and adapted to receive the gas-entrained material from the extinguisher, oppositely disposed shoulders at the end of said bore within said body and projecting at right angles to the walls of said bore, said shoulders terminating at their inner ends in walls parallel to the longitudinal axis of said bore and parallel to each other, the combined cross-sectional areas of said shoulders extending across said bore being equal to approximately one-third the total cross-sectional area of said bore, and said face having a diffusing slot therein defined by said parallel walls and side walls extending from the inner end of said bore outwardly to said face, said side walls flaring outwardly from each other toward said face at a total included angle of approximately eighty degrees to provide for dispersion of said material in a continually laterally widening spray pattern.

6. In a diffuser tip for a dry chemical fire extinguisher nozzle for producing a blanket of substantially uniform consistency approximately twelve feet in width at a range of about ten feet from the nozzle when subjected to a pressure of approximately pounds per square inch from within the extinguisher, the combination of a cylindrical tip body adapted for attachment at one of its ends to the outlet of said extinguisher nozzle, said body terminating in a flat face at its other end, said body having a circular bore extending coaxially therein from said one end through a major portion thereof and adapted to receive the gas-entrained material from the extinguisher, oppositely disposed shoulders at the end of said bore within said body and projecting at right angles to the walls of said bore, said shoulders terminating at their inner ends in upper and lower walls parallel to the longitudinal axis of said bore and parallel to each other, the combined cross-sectional areas of said shoulders extending across said bore being equal to approximately onethird the total cross-sectional area of said bore, said face having a difiusing slot therein defined by said parallel walls and side walls extending from the inner end of said bore outwardly to said face, said side walls being rounded to merge smoothly with said upper and lower walls, and said side walls flaring outwardly from each other toward said face at a total included angle of approximately eighty degrees to provide for dispersion of said material in a continually laterally widening spray pattern having a total included angle of about sixty degrees.

7. A difiusing nozzle for a dry chemical fire'extinguisher comprising a nozzle casing having a passage therethrough adapted for connection to a supply of comminuted chemical material and pressurizing gas to conduct a'stream of such material entrained in the gas to the outlet of said passage, a diffuser tip supported at the outlet end of said passage in freely open communication with the atmosphere, said tip having a face at the open end thereof and a bore extending from the other end to adjacent said face, said face having a diffusing slot therein communicating with said bore, the upper and lower walls of said slot being substantially parallel to each other and terminating along parallel lines spaced across the end of said bore by a distance less than the diameter of said bore to provide shoulders at the adjacent end of said bore on either side of said end of said slot and extending substantially transversely of said bore for creating turbulence in the gas-entrained stream of comminuted chemical material issuing from said tip, and the lateral walls of said slot diverging from said end of said bore to said face relative to each other for dispersing said material in a continually laterally widening spray pattern.

References Cited in the file of this patent UNITED STATES PATENTS 2,484,943 Guise et a1. Oct. 18, 1949 

